The present invention relates to an electric jack adapted for mounting on a mainboard in a telephone network or local area network for receiving a module plug from an external signal line, and more particularly to such an electric jack which comprises a filter module fastened to a terminal block thereof to eliminate noises from incoming signal passing to the mainboard.
A regular electric jack for mounting on a mainboard in a telephone network or local area network for receiving a module plug from an external signal line, is generally comprised of a plastic shell, a terminal block mounted inside the plastic shell and holding a plurality of terminals, and a metal shell covered on the plastic shell to eliminate external electromagnetic interference. When an electric jack of this structure is mounted on a mainboard in a telephone network or local area network, the terminals of the electric jack are connected to respective electric contacts on the mainboard. Further, in order to eliminate noises from incoming signal passing to the mainboard, a filter circuit is needed. A filter circuit for this purpose is directly installed in the mainboard circuit. However, the installation of this filter circuit occupies much mainboard space, and complicates the arrangement of the circuit on the mainboard.